Bellows folding machine



8' 1954 c. B. ROWLAND ETAL BELLOWS FOLDING MACHINE Filed Nov.- 4. 194a 5 Sheets-Sheet l attorneys Aug. 3'], 1954' Filed Nov. 4, 1948 C. B. ROWLAND ET AL BELLOWS FOLDING MACHINE 5 Sheets-Sheet 2 Aug. 31, 1954 c. B. ROWLAND ET AL BELLOWS FOLDING MACHINE 5 Sheets-Sheet 3 Filed NOV. 4. 194B 3 rwen tors .vzvzv f g- 31, 1954 c. B. ROWLAND ETAL 2,687,678

BELLOWS FOLDING MACHINE Filed NOV. 4, 1948 5 Sheets-Sheet 4 Jrwentors Patented Aug. 31 1954 BELLOWS FOLDING MACHINE Clare B. Rowland and CW Mich, assignors to Gen Detroit, Mich., aueorp Application November 26 Claims.

This invention relates to machines for folding sheet material, "and more particularly for folding a tube of sheet material into a bellows.

The object of the invention is to fold a long tube 'of sheet material rapidly and accurately into a po ygonal bellows.

Another object of the invention is to provide a hold the sheet material in contact with the foldi'ng hinges of the machine during the folding operation.

a plurality of similar series of slidably mounted folding hinges. Each series, whiehhas a multiplicity of slidaoly mounted folding hinges, may be Figure l is a ve'rueal elevation with Certain parts broken 'awa Figure is an enlarged perspective View of afold plate.

Figure 5 is an enlarged fragmentary vertical section with certain parts broken away and shown in section.

Figure 6 is a fragmentary view of a portion of Figure 5 showing the fold plates in the expanded position. Figure 7 is a fragmentary view ofa portion of Figure 5 showing the fold plates in the compressed position.

'Figure8 is an exploded perspective View showi'n'g the details and relative position of the slidihg block's.

en A. Christensen, Flint, eral Motors Corporation, oration of Delaware 4, 1948, Serial No. 58,262

Figure 9 is a fragmentary "enlarged cross sec-- tionalview.

Figure 10 is a perspective View of a partially folded bellows.

foldplates are then successively folded. inwardly to form the pleats. Polygonal bellows having more than eight sides may be made by employplate l2 and a pair of bottom guides I3 positioned along each edge of the bottom plate are secured to the base I 9. A guide slot I4 is formed by a recess at each longitudinal edge of the bottom plate 42 and the side of the bottom guides I3 to guide the side blocks It. The side folding hinges i! are pivotedto side blocks Hi. The guides [3 have grooves I8 to guide the bottom blocks 20 which support the bottom series of folding hinges H.

A series of cover supports 25 are mounted on the base ill have a boss 24 engaging the cover 't the cover assembly. The upa means to lock the cover in position as described below.

In Figures 1 to 3 the cover 21 is 'shownin full lines in the raised or opened position, while in Figure 3 the dot-and-dash lines show the cover in the closed operating position. The supports are recessed to fit flush with the inner edge of the guides 13 and are secured to the base.

A top plate 28 similar to bottom plate I2 is secured on the under side of the cover and a pair of top guides 29 are secured to the cover along the side edges of the top plate. A pair of guide slots 3| for the upper ends of the side blocks It are provided by a recess along each edge of the top plate and the adjacent side of the top guides. An elongated longitudinal top groove 32 is pro vided in the inner side of the top guides 29 to hold the top blocks 33 which support the top series of folding hinges H.

In order to facilitate movement of the cover assembly from the open position to the closed position shown in dot-and-dash lines in Figure 3, the cover is counterweighted. A pair of pulleys or gears 36 are fixed to a shaft 31 suitably supported above the cover by means, such as posts 38 mounted on the supporting frame II. A pair of chains 39 extend over the gears 36 and are attached at one end to the cover 2'! by the link ti! and at the other end to the counter-weight 42. The gears 36 are fixed to the shaft 31 to maintain the cover in horizontal position.

A locking mechanism is mounted on the cover to lock it in either opened or closed position. The lock mechanism is operated by a handle M fixed in the trunnion 45 which is pivotally mount ed on the cover 21. A pair of discs 45 are secured to the trunnion in spaced relation to operate similar toggle looks at each end of the cover. One end of each connecting link 41 is pivotally connected between the discs 46 on opposite sides of the trunnion 45. The other end of each link A! is pivoted to a rod 48 reciprocally mounted in guides 49 which are fixed to the cover. Each rod 48 is pivotally connected to toggle links 52 and 53. Each toggle link is pivotally connected to a locking bolt 54 which is reciprocally mounted in guide 55. Thus it will be seen that there is one locking bolt 56 adjacent each corner of the cover, and that all the bolts are simultaneously operated by the centrally located handle M.

In order to secure the cover in open position the lock bolts 54 engage latches 5'! suitably mounted above and supported on arms 58 fixed to the posts 38. As the cover 2'! is lowered it is guided by plate 59 fixed on post 38 and will pass between the lower latches til. Then the bolts 54 may be extended to lock the cover in closed position. In order to guide the cover into either end position the ends of the upper and lower latches 51 and iii! are bevelled and are spaced slightly further apart than the width of the cover The final positioning of the cover occurs when the guides 29 engage the inner edge of the guide portion 26 of the supports and rest on the supports 25.

The four longitudinal series of folding hinges H which form the pleats in the tube to form the bellows extend substantially throughout the length of the machine. Since all the folding hinges are the same and the mounting blocks in each series are the same, the details are shown in Figures 4, 5, 8 and 9 which illustrate a section of each series.

Referring to Figure 9, which shows a cross section of the slide blocks and fold plates with the cover 21 in closed position, it will be seen that the top guides 29 with the top plate therebetween and the bottom guides l3 with the bottom plate therebetween form an elongated frame having square cross section. A series of slide blocks l6 are located at each side of this frame with the upper end in guide slot 3! and the lower end in guide slot m. The blocks is on opposite sides of the frame face each other and are intransverse alignment. Between each side block it is positioned at the bottom a bottom guide block 29 and at the top a top guide block 33.

The folding hinges H as shown in Figure 4 are trapezoidal in shape and have conventional pintle journals 6! on the short base of the trapesold and pintle journal 62 on the long base of the trapezoid. A pair of folding hinges H are hinged together by passing a short pintle 63 through the short journals. As shown in Figure 9 the short pintle 53 extends at each end beyond the journals 6% and enters the eye of the studs M to secure the folding hinges to the side slide blocks iii. A folding hinge I! will then extend from each slide block it": toward the adjacent slide block on the same side. The long journals 62 on the long trapezoidal base mate and are hinged together by the long pintle 6E. The whole series of side blocks iii on each side are thus connected together by the folding hinges ll.

Similarly folding hinges ii are hinged by pintles E33 and studs 64 to'the bottom blocks 2%] and top blocks 33. The bottom and top folding hinges are also hinged together in a continuous series by long pintles 65.

The ends of the slide blocks overlap and thus must have interfitting recesses so that they may be moved together to move the hinges inwardly to form the pleats. As best shown in Figure 8 the side slide blocks 98 have recesses 58 adjacent the base which interfit with recesses 69 adjacent each end of the bottom slide block .29, so that both the side blocks it and the bottom blocks 2!] can be moved together until the side faces contact. The top slide block 33 has recesses H at each end similar to recesses 59. The top end of the side blocks I6 have open recesses l2 on each side. These recesses similarly enable the side block and the top blocks to be moved together. The recesses '12 are opened to allow the top block 33 which is mounted in the cover 21 to be removed with the cover. I

The ends of the long pintle 55 pivoting the hinges I1 mounted on the side blocks Hi extends into a slot 14 in the bottom block 28 and a slot [5 in the top block 33. The slot E5 has bevelled edges to correct any misalignment of the long pintle and the top block 33 when the cover is placed on the machine. The side blocks H3 also have centrally located slots E5 to provide a guide for the ends of the pintles 650i the hinge series mounted on both the top blocks 33 and the bottom blocks 2%. The top ends of the slots H5 in the side blocks It are bevelled both laterally and transversely to correct any misalignment when the cover is positioned.

In order to move the blocks from the closed position to the opened position each of the side slide blocks is has a leaf spring 18, as best shown in Figure 5 attached in a slot 19 in each side edge of the side blocks 16. The leaf spring 18 has a central bight til that engages and is secured by a pin 8| passing through an aperture in the block. Similar slots 83 and 84 are formed in each side edge of the bottom block 20 and the top block 33 respectively to provide a space for springs 18 secured in the same manner by a pin 8! extending through an aperture in the blocks. The springs a 18 extending from adjacent sides of each pair of e 104 1s returned to the r l jaw; TWO sets of spring-attested return 'I'ods in Figure '2 at the fixed eta of the are s twn'in FigiiieQ.

As shown maehmeg a top abutment b l'oek as is attached to tthe movable end ojfithe srieslof fold plates the top plate 28, or retained in th'e guide grooves fend bottom bloek zfl -has a pair of ears I I5 32 by the end plateflil, o provide a stop for the an ar a ertures te ece ve afs'orevv 6 to withthe recesses lifb'n thelas t pair or oppositely sponge rubber bulSlfi hg H 9, vv't'hit'rh may fit ihto disposed side bloeksflfi. A similar lower abutthe end of the paper tube butp'rjeferably abuts inent blocktm as b'est shovvn in Figure 5, has sum 7 the end of the tube, as -showlflin Figure 5. The ilar=recesses a't eaeh endtoint'erengage with the '20 head U1 is seeured at the bottom to a guide recesses 68 at the lower end of the side blocks I6. plate 12 0 Wh-ieh slides the greets-s ls on the onthefull-Width blo" ks. The and foldplate H Thus the head H1 will move both the ehd top u id f h endplate 93, as best sh wn in side bloeks 1'6 and to adjaee'r'it top and bottom Figure 5. The suppert 5'0 is'as wide as the short blecks thio'ugh springs 18. The spae'er H8 is end of a fold plate and has a lateral journal por- 3'0 znade substantially as Wideas the head I I1, and

plate 93. The journal portion 99 terminates in It when the hinges are'folded completely inward W p t pport journals similar to the join as shown in Figure 7. The spacer H8 is out nals on the short side of the trapezoidal hinge away at both the top and bbttom to provide plates 11. The pintle journals on p r on 99 ar 3-5 clearance for the folding hinges; The head I I7 interfitt'ed with the pintle journals 6| on the last is dfifiefed by pi to rad 12"] to t it ble hinge I! and are pivota ly secured to e her by a source of power such as "a hx draulic "piston (not short pintle 83. The bottom end plate 93 is suitshown), ably recessed above the aperture to provide clear- I forming bellbwgwith this folding inaance for the last hinge plate l7. Thetop pintle chi e th pap first Ii-6119a" late 9| i a a e to the over 21 and where it rests on the bott'dih series of folding central semi-circular 9 as shown In hinges n and is cbhfinedbythe Side series fold- Flgure 3. A similar lower d plate 93 15 ing hinges l1. Then the cover 21 is unlocked ly asshown in Figure 5 to receive the fixed end Then the handle N16 is moved to rotate cam of the paper u I 26 nd to p an m4 and clamping jaw 95 to grip the tube bernent for the tubular clamp n jaw 95 which has tween the clamping javvand the end plates. Figa mating bevelled front edge. ure 5 shows the lower end plate 93 and the The clamping jaw 95 is lid bly mo n d on clamping jaw 95 gripping the tube I26. one end of the air inductlon tube 96 WhlCh is Then air under pressure is supplied through supported at the other end 1n fixed positlon by the inductor tube 96 to h'o'l'd the paper tube I26 tube support 91 mounted on base It! The clampagainst the folding hinges I7, and the head H1 supported by a journal 98. The clamping jaw and engages the first top block 33 in the open 95 is reoiprocatecl in the journal 98 by a cam and position shown in Figure 6, with the hinge plates rotation is prevented by the pin [ill in the jourl1 abutting the stops 82 to prevent locking.

1134. The tubularcam hasan operating handle in the intermediate side block and maintains I 56 and preferablyabutson the bearing thisblool; midway between the top and bottom -|-8'7tvh ioh is elainpedbn the air induetion tube blocks. Similarly the top and bottbm bloelis are maintained midway 7 between the bottom blocks. This interlocking arrangement of the top and bottom and the side blocks determines the relative movement of the blocks and hinges. When the head I 11 starts to move the first top and bottom end blocks, the first pair of side blocks will move at half speed and the second pair of top and bottom blocks will move at quarter speed. Theoretically each successive pair of blocks will move at one-half the speed of the preceding pair of blocks. However, due to the necessary clearance between the parts this movement diminishes more rapidly and is not noticeable after the fifth to tenth block. When the bottom and top blocks engage the side blocks at the bottom of slots 68 and the head spacer H8 engages the side blocks, they will move at the same speed as the head and transfer the movement in the same manner to successive blocks. Thus the blocks will move together progressively in a wave. Since the blocks are moved by force transmitted through the hinges I1 and the long pintles 65, springs 18 are inserted between the blocks to transmit some force from block to block before the blocks are in actual contact, and thus remove some of the load from pintles 65. Thus as the head moves toward the fixed end of the machine, the top and bottom hinges and then the side hinges will move together alternately and progressively in a wave formation to pleat the paper tube I26. When all of the folding hinges are in the completely closed postion as shown in Figure '7, the tube will be formed into a bellows as shown in Figure 10. The air supply is stopped.

Then the cover 21 is unlocked and raised to open the machine and the head H1 is returned by the power cylinder to the opened position. The tube which is creased to form a bellows but in elongated form is removed.

The return movement of the head H1 will draw the folding hinges I! mounted on the side blocks l6 and the bottom blocks 20 to the opened position due to the fact that the last bottom block 20 is secured by screw H6 to the head. However, when springs are located between these side and bottom they will return the folding hinges with substantially no load on the head H1. The springs between the top blocks 33 are preferably'made strong enough to return the block to opened position. Thus the top folding hinges will return to the opened position when the cover is raised, and thus the cover can be raised before the head is returned to the opened position without requiring a hand operation to return the top series of fold plates.

The above described specific embodiment is illustrative of the invention. Other modifications within the terms of the appended claims will be apparent to those skilled in the art.

We claim:

1. In a machine of the character described, a frame, means to supply compressed air to the interior of a tubular blank, sealing means secured on said frame to clamp one end of the blank, sealing means slidably mounted on the frame to seal the other end of the blank, a plurality of series of folding members arranged about said tube, the folding members of each series being hinged together, a plurality of slide blocks mounted in said frame, alternate hinges between said members being pivoted to said blocks, means to move said blocks and slidably mounted sealing means toward the other sealing means to form said tube into a bellows.

2. In a machine of the character described, a

prism-shaped frame, means adjacent one end of the frame to supply compressed air to the interior of a tubular blank, means fixed to said frame to seal one end of the blank, means slidable on said frame to seal the other end of the blank, a series of blocks slidably mounted on each side face of said prism-shaped frame, a folding plate pivotally mounted on each slide block, said folding plates mounted on adjacent blocks of each series being hinged together, means to move each block toward the fixed means whereby said folding plates move inwardly to fold said tubular blank into a polygonal bellows.

3. In a bellows folding machine, a supporting frame, means mounted on the machine axis on said supporting frame to clamp one end of a tubular bellows blank, means mounted on the machine axis on said supporting frame to seal the other end of the tubular blank, means to supply air under pressure through said clamping means to said tubular blank, a plurality of series of hinged fold plates positioned about said axis and each series extending along said axis, said fold plates being movable inwardly toward said axis to form said tube, a plurality of series of blocks supported on said supporting frame for longitudinal sliding movement, and each fold plate being pivotally mounted on one of said blocks.

4. In a machine of the character described, a supporting frame, fixed sealing means mounted on said supporting frame to secure one end of a tubular blank, a movable sealing means mounted on said supporting frame and sealing the other end of said blank, means to admit compressed air to the interior of the tube through one of said sealing means, a plurality of series of folding members having straight edges, the adjacent the folding members of each together, alternate series of said folding members having the straight edges engaging the paper spaced between the straight edges of the intermediate series, means mounted on said supporting frame to guide said folding members and means to move said folding members inwardly in sequence commencing with the end alternate folding members and then the adjacent intermediate folding members, and said folding members at the same time moving longitudinally toward the fixed sealing means.

5. In a machine of the character described, a prism-shaped frame having a plurality of fixed longitudinally extending faces, means adjacent one end of the frame to supply compressed air to the interior of a tubular blank, means fixed to said frame to seal one end of the blank, means slidably mounted on said frame to seal the other end of the blank, a series of slide blocks longitudinally slidably mounted in fixed lateral relation to each side face of said prism-shaped frame, a folding plate mounted on each slide block, means to move each folding plate inwardly to fold said tubular blank into a polygonal bellows.

6. In a machine of the character described, means to internally support a tubular bellows blank, a fixed prism-shaped frame having a plurality of longitudinal side faces surrounding said blank, a series of blocks mounted for longitudinal sliding movement along each side face of said prism-shaped frame, a fold plate pivotally mounted on each block, means to move said blocks with straight longitudinal movement and in fixed lateral relation to the frame toward one end of the frame, and means responsive to longitudinal movement of said blocks to move said plates toward each other to fold said tube into a bellows.

'Z. In a machine of the character described, a each member in each series toward each other' supporting frame, means to internally support a and tomove the folding plates toward each other tubular bellows blank, a plurality of series of fold and inwardly to fold. said tubular blank into a plates positioned to form a tunnel surrounding polygonal bellows. the tubular bellows blank, hinge means pivotally 13. In a bellows folding machine, a frame,

ing said plates longitudinally and inwardly. of hinged fold plates having adjacent plates of a 8 In a machine of the character described series hinged together, each series of hinged fold means for internally supporting a deformable platesextending longitudinally along he machine tubular blank a supporting frame having a pluaxis between said means to seal both ends of the rality of longitudinally extending sides forming tubular blank, said plurality of series of hinged a tunnel enclosing said tubular blank, a plurality fold plates being transversely grouped about the fold plates hinged to each block, each of said form said tubular blank, and each fold plate of plates being hinged to another plate, means to 0 said series being hinged to the adjacent fold move said blocks toward one end of said frame plate.

of slide blocks mounted in said frame, alternate each of said fold plates being d e t y hinged hinges between said members being pivoted to another fold plate. said blocks, means to move said blocks toward 15. In a machine of the character described each other to move the alternate hinges toward for folding a tub b a k into a folded b W each other and the other hinges moving toward a uppor n f m m ns o intern lly upp r each other and inwardly to form the tube into a a fi ar l o g the machine a Supp bellows. ing means slidably mounted on said supporting 10. In a machine of the character described frame for guided straight line movement longifor folding a tubular blank into a folded bellows, tudinallyalong the machine ax s, fol pl t s D a prism-shaped frame, means to provide aninteri d to Sa d supi lt means nd Suppo nal yieldable support during the folding operathe tubular blank, means to move said support tion for a tubular blank positioned in said prismmeans longitudinally and to swing said plates shaped frame, a series of blocks slidably mounted toward'each other and to swing said plates transon each side face of said prism-shaped frame, a versely inwardly toward the machine axis to form folding plate pivotally mounted on each slide the tubular blank into a folded bellows. block, said folding plates mounted on adjacent 1 1 a a e OI the Character described, a blocks of each series being hinged together, means frame, means to. provide an internal pport f to move said blocks toward each other and to. a tubular blank during the folding operation, a move said folding plates toward each other and p ural y of series of f n m m s rr n inwardly to fold said tubular blank into a polyabout the tubular blank, the folding members of gonal bellows, each series being hinged together, mean to slidll. Ina machine of the character described for y pp alternate es e w n Said memfol ling a tubular blank into a folded bellows, a erson aid frame, and meansto move said altersupport for a tubular blank dur ng foldmg 0pdiate hinges moving toward each other and 111- eiations, a plui ality of series of foldmg members Wa y o m t e tubular blank into a folded arranged about said tube, the folding members of bellowseach series being hinged together, a plurality of 17. In a machine of the character described, a

slide means mounted in said frame, alternate f me, m ans to support a tubular blank during said slidemeans means to move said slidemeans mg members arranged about the tubular blank,

toward each other and to move the alternate hinge means between the folding members of each hinges toward each other and the other hinges Se ies hlnging said members together, means to moving toward each other and inwardly to form S dably upp t alternate hinge means on said th t b i t folded bell frame, and means to move said alternate hinges 12, In a hi of th -char ct d ib d toward each other and the intermediate hinges for folding a tubular blank into a folded bellows, m ving toward each other and inwardl to form ame, means to provide an inthe tubularblank into a folded bellows. ternal yieldable supportduring the folding opera- 18; In a machine of the character described, a

prism-shaped frame, a series of members slidably means mounted on said supporting frame along each series being hinged-together, means to move the axis, means to admit compressed air to the interior of the blank through said fixed clamping means, a plurality of series of folding members having straight edges extending transversely of said axis, the straight edges of alternate series of said folding members engaging the blank spaced between and transversely angularly displaced from the straight edges of the intermediate series of folding members, means movably mounted on said supporting frame and supporting said members individually on the supporting frame for controlled movement inwardly in sequence commencing with the end folding member of one series and then the adjacent folding member of the other series until all the folding members move inwardly and means to move said folding members for said controlled movement.

19. In a machine of the character described, a supporting frame having an axis, means to provide support for the interior of a tubular blank located coaxially of said frame axis, folding means having tube engaging edges mounted on said supporting frame to form the tubular blank into a polygonal bellows consisting of a plurality of axially extending series of folding members grouped transversely about the tube, the edges of the folding members of each series being positioned transversely with respect to the axis and adjacent members of the respective series transversely angularly related, mounting means to mount said folding members individually on said frame for controlled longitudinal movement and for inward movement inwardly in a sequence starting with the end members of one series, then the axially adjacent members of the other series until all the members are moved inwardly.

20. In a machine of the character described, a supporting frame, means to supply compressed air to the interior of a tubular blank, means mounted on said supporting frame to seal one end of the blank, means movably mounted on said supporting frame to seal the other end of the blank, a plurality of series of trapezoidal folding members arranged in a first position in a generally tubular form about the tubular blank and movably mounted on said supporting frame, the bases of said trapezoidal members being movably interconnected in series for movement from said tubular form to a second position forming a surface having the shape of a collapsed polygonal bellows having trapezoidal sides, and means to move said members inwardly from said first position to said second position to form a surface having the shape of a collapsed polygonal bellows form to shape the blank into a polygonal bellows having trapezoidal sides.

21. In a machine of the character described, a supporting frame, means to supply compressed air to the interior of a tubular blank, fixed means mounted on said supporting frame to seal one end of the blank, movable means mounted on said supporting frame to seal the other end of the blank, a plurality of series of trapezoidal folding members arranged in a generally tubular form about the tubular blank, said plurality of series of trapezoidal folding members being movably mounted on said supporting frame and the trapezoidal folding members of each series being hinged together in series for movement from said tubular form to form a surface having the shape of a collapsed polygonal bellows, means to move alternate hinged portions of each series of said members inwardly and toward said fixed means to form a surface having the shape of a collapsed polygonal bellows form to shape the blank into a polygonal bellows.

22. In a machine of the character described, a supporting frame, means to internally support a deformable tube for forming a bellows, a plurality of pairs of folding plates surrounding the tube, said pairs of folding plates being hinged together at one point, means to movably support said pairs of folding plates at other points on said supporting frame, and direct machine actuating means to move said other points of said pairs of plates together in sequence, with each successive pair of folding plates moving slower than the precedingpair of folding plates.

23. In a machine of the character described, a supporting frame having an axis, means to internally support a tubular blank coaxially along the frame axis, supporting means slidably mounted on said supporting frame for guided straight line movement longitudinally of said supporting frame along the blank and machine axis, fold plates mounted on said supporting means providing support for the tubular blank in one position, said fold plates and said support means being pivotally interconnected to move the fold plates inwardly in response to longitudinal movement of said support means, means to move said support means longitudinally to move said fold plates longitudinally and to swing said plates inwardly toward said axis of said supporting frame.

24. In a machine of the character described for folding a tubular blank into a folded bellows, a supporting frame having a longitudinal axis, means to internally support a tubular blank along the longitudinal axis, a plurality of fold plates arranged in a generally tubular form positioned coaxially with the axis of said frame and around the tubular blank and providing an external support for thetubular blank, each of said fold plates having pivot means to slidably and pivotally support said fold plates on said supporting frame, means interconnecting said plates to move said plates longitudinally along the axis of the frame and including means responsive to the longitudinal movement of said fold plates to move said plates toward each other and inwardly toward the machine axis to form the tubular blank into a folded bellows.

25. In a machine of the character described, a supporting frame having a longitudinal axis, means to supply compressed air to the interior of a tubular blank located coaxial with said axis, a

fixed seal mounted on said supporting frame to close one end of the blank, a movable seal mounted for axial movement on said supporting frame to close the other end of the tubular blank, folding means mounted on said supporting frame to form the tubular blank into a polygonal bellows consisting of a plurality of axially extending series of folding members arranged longitudinally along the axis of the frame about the tubular blank, each of said folding members extending transversely, the transversely adjacent folding members being at an angle to each other, the folding members of each series being positioned between the members of the adjacent series, means longitudinally movable on said supporting frame, and said folding members being pivotally mounted on said longitudinally movable means for longitudinal movement along said axis and movement transversely toward said axis.

26. In a machine of the character described, a supporting frame having a longitudinal axis, means to supply compressed air to the interior of a tubular blank locatedcoaxially of the axis, means mounted on the axis of said supporting frame to close one end of the blank, meansmount-,

ed on the axis of said supporting frame to close wardly toward the frame axis in a sequence, said the other end of the blank, folding means mountsequence including first moving the end members,

of series of foldin menlilbers rran e m References Cited in the file of this patent versely in a group about t e blank loca ed a ong the frame axis, each of said folding members 10 UNITED STATES PATENTS extending transversely, the transversely adjacent be Name Date folding members being at an angle to each other, ,1 3,1 Balsam July 12, 1938 movable means interconnecting said folding 2, 9,4 Probst Mar. 7, 1939 members mounted on said frame to allow con- 2,169,205 Horning Aug. 8. 1939 trolled movement of said folding members in- 15 

